The present invention relates to orientable beam antennae and more particularly those for use in the spatial vacuum, on board telecommunications satellites.
These antennae comprise mechanisms, involving bearing and sliding frictions, whose construction, with the high degree of reliability required for equipment carried on board satellites, constitutes a difficult and costly problem to resolve.
It is known to construct such antennae by means of a fixed device comprising a primary source illuminating a first reflector and a second mobile reflector illuminated by the preceding one. But the present constructions do not allow more than 2.degree. or 3.degree. of movement to be obtained, whereas it is desirable to obtain orientation variations of the radiated beam of at least .+-.30.degree..